Total amino acids and fatty acids composition of yam (Dioscorea) tubers and their evolution during storage

Abstract

AbstractThe qualitative and quantitative analysis of total amino acids from tubers of six yam species (Dioscorea) and fatty acids from five yam species has been done by gas—liquid chromatography. For amino acid analysis, the results obtained show that hydrochloric acid hydrolysates of yam flours contain most of the amino acids from proteins in high concentration. In the fatty acid analysis, 11 saturated fatty acids, with 12 to 25 carbon atoms, and five unsaturated fatty acids, with 16, 18 or 20 carbon atoms, were identified. Palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2) and linolenic acid (18:3) are the most abundant fatty acids found in yam tubers. Comparative analysis of yam tubers stored for 1, 5 and 8 months after harvest shows that the total amino acid content decreases slightly and fatty acid content increases during the storage period. No significant change was observed in the composition of total amino acids and fatty acids from yam tubers stored at 25°C for several months.